The brain and spine are covered with a tough outer membrane called the dura mater, or dura. During surgical procedures, e.g., spinal surgery, the dura mater may be opened intentionally or inadvertently. Such an opening is called a durotomy or dural tear. Dural tears requiring closure or repair have been reported to occur in a significant percentage of surgical procedures. In some approaches, sutures are used to repair or close the dura. Durotomies must be closed prior to closing the skin. Failure of the closure can result in persistent cerebrospinal fluid (CSF) leakage, for example. This leakage may result in wound breakdown, spinal headaches, infection, meningitis, and other consequences.
Minimally invasive surgeries (MIS) are becoming more commonly used during surgical procedures, e.g., to treat a variety of pathologies including herniated discs, spinal stenosis, synovial cysts, spondylolisthesis, deformity, intradural tumors, etc. Such procedures use smaller incisions to decrease intraoperative blood loss, reduce tissue disruption, decrease postoperative pain, and decrease lengths of hospital stays, for example.
Minimally invasive surgeries make use of smaller ports and result in less tissue disruption than traditional procedures. However, should a durotomy occur using a minimally invasive surgery, closure of the dura can become extremely difficult or impossible due to the small size of the incision. For example, in the setting of minimally invasive spine surgery, the ability to close a durotomy may be compromised when suture material cannot be manipulated sufficiently to achieve tight closure. Thus, due to the physical limitations of small working areas, repair of a durotomy may be technically difficult and time-consuming when using conventional suture and knot-tying techniques.
In order to overcome these technical difficulties resulting from minimally invasive surgeries, metal staples, such as titanium staples, delivered via a suitable applicator may be crimped or bent from an open position into a closed position around the tissue edges to close a hole in a tissue such as a durotomy. However, in such approaches, it is necessary to place the staples sufficiently close together along a dura tear in order to close the tissue since such staples may be too thin to cover and hold significant lengths along the tissue break. Further, use of metal staples or clips either results in a permanent foreign body left in the tissue or a second surgical intervention to remove the staples or clips. Clips or staples left in the tissue may interfere with postoperative imaging resulting in undesirable artifacts in radiographic imaging such as magnetic resonance imaging (MRI) and computed tomography (CT) scans.